5

Application information

5.1

Overview

The TSC200, TSC201, and TSC202 devices are designed to measure current by amplifying the voltage across a

shunt resistor connected to its input. Thanks to a bandgap reference and a comparator, which is able to latch the

output, the TSC20x family is the perfect candidate for overcurrent protection.

TSC200, TSC201, and TSC202 are current-sensing amplifiers with a respective gain of 20 V/V, 50 V/V, and 100

V/V. They provide an extended input common range from -16 V up to 80 V, while the devices can operate from

2.7 to 18 V. They can operate either as low side or high side current sensing amplifiers.

The parameters are very stable in the full VCC range, and several characterization curves show the characteristics

of the TSC20x devices at 12 V. Additionally, the main specifications are guaranteed in extended temperature

ranges from -40 to 125 °C.

5.2

Theory of operation

The main feature of the TSC200, TSC201, and TSC202 is the ability to work with an input common-mode voltage

largely beyond the power supply VCC range (2.7 V to 18 V). It is ideal, for example, in wireless infrastructure

equipment to monitor the current flowing into a power amplifier. The integrated comparator and reference output

allows for an overcurrent protection implementation.

The internal topology used in the TSC200, TSC201, and TSC202 is different from a classic instrumentation

amplifier approach. The TSC20x family offers a high CMRR, without any special care towards the internal

resistance matching and low input bias current.

Nevertheless, this topology implies three operation functional modes for the TSC20x. These modes are a function

of two main variables: the differential input voltage Vsense (resulting in a current flowing into the shunt resistance)

and the input common-mode voltage Vicm, relative to the supply voltage VCC.

Mode 1: Vsense > 20 mV and Vicm > 40% VCC

Figure 29 depicts a simplified diagram, explaining the main functional principle of TSC20x for the mode 1

operation.

Figure 29. Simplified diagram when Vicm > 40% VCC

+

-

D

D

D

+

-

GND

OUT

VIN+

Vcc

Vicm>40%Vcc

+2.7V to +18V

Load

R1

R1

R2

A2

A1

A3

VIN-

Reference

voltage

0.6 V

CMPOUT

CMPIN

RESET

+

-

Ir

Ir

Ir

ILoad

Vsense

12.5kΩ

5kΩ

V2

-

TSC200, TSC201, TSC202

Application information

DS13882 - Rev 2

page 12/34